In China in 2003, twin babies Mia and Alexandra were found in a cardboard box and placed in an orphanage, where authorities separated the infants and concealed their sibling relationship. Two sets of prospective adoptive parents — one from California and the other from Norway — meet during the adoption process and launch an investigation that reveals that the girls are sisters. The girls grow up knowing they have a twin living on the other side of the world. When the girls are eight, Mia and her family go to Norway to visit Alexandra, and discover that the girls not only look and act alike, but are unmistakably and inextricably connected to each other.